Field of the Invention
The present invention relates to a display device, and more particularly, to a structure of connecting a panel driver to a side of a display panel and an electrostatic discharge structure.
Discussion of the Related Art
Display devices such as a liquid crystal display device, a plasma display panel, and an organic light emitting display device have been developed up to now.
The display device includes a display panel for displaying an image, and a panel driver for driving the display panel. Hereinafter, a connection structure of a display panel and a panel driver according to the related art will be described.
FIG. 1A is a brief plane view illustrating a display device according to the related art. FIG. 1B is a cross-sectional view taken along line I-I of FIG. 1A.
Referring to FIGS. 1A and 1B, the display device according to the related art includes a lower substrate 10, an upper substrate 20, a flexible circuit film 40, and a printed circuit board (PCB) 50.
A display panel is formed by combination of the lower substrate 10 and the upper substrate 20, and a panel driver is formed by combination of the flexible circuit film 40 and the printed circuit board (PCB) 50.
The lower substrate 10 is provided with various signal lines, and a signal pad 11 is provided at an end of the signal line. The signal pad 11 is connected with the flexible circuit film 40. In more detail, the flexible circuit film 40 is attached to an upper surface of the signal pad 11. To this end, the upper surface of the signal pad is exposed. That is, the lower substrate 10 is more extended than the upper substrate 20, and the signal pad 11 is formed on the extended lower substrate 10. The flexible circuit film 40 is connected with the printed circuit board (PCB) 50.
In the aforementioned display device according to the related art, the flexible circuit film 40 is attached to the upper surface of the signal pad 11. Therefore, a problem occurs in that a bezel area is increased to expose the upper surface of the signal pad 11. Also, there is limitation in realizing a display device of various esthetic senses due to a step difference in the bezel area.
FIG. 2 is a view illustrating an electrostatic discharge (ESD) structure of a display device according to the related art.
Referring to FIG. 2, in the display device according to the related art, for electrostatic discharge, a transparent conductive layer 22 of a transparent conductive material such as indium tin oxide (ITO) is formed on an upper substrate 20, and the transparent conductive layer 22 of the upper substrate 20 is electrically connected with an electrostatic pad 12 arranged on the lower substrate by using a connection electrode 30. At this time, the connection electrode 30 may be made of Ag having excellent conductivity. And, the electrostatic pad 12 is electrically connected with a case top 70 by using a chip on film (COF) 60.
In the electrostatic discharge (ESD) structure of the display device according to the related art, since the upper substrate 20 should electrically be connected with the lower substrate 10 by using the connection electrode 30 and the lower substrate 10 should electrically be connected with the case top 70 by using the COF 60, a problem occurs in that a bezel area is increased. Also, a process of forming the electrostatic discharge structure is complicated, whereby problems occur in that productivity is deteriorated and a manufacturing cost is increased.
Recently, a video wall display device has been developed, which realizes a large-sized display by arranging a plurality of display panels in a tile pattern. If the bezel area of the display panel is increased, an external esthetic sense of the video wall display device is deteriorated. Particularly, an interval between the display panels is increased so as not to smoothly display an image, whereby a problem occurs in that display quality is deteriorated.